This invention relates generally to window locks and more specifically to methods and apparatus for a single lever tilt lock latch window.
This invention relates to the field of tilt-in windows. More particularly this invention relates to a tilt lock latch mechanism that locks a first window sash to a second window sash to prevent relative sliding movement between the window sashes and also allows the first window sash to be tilted relative to the second window sash and the window frame.
Typical double hung windows include two window sashes disposed in tracks located in a window frame to allow vertical sliding movement of the sashes in the window frame. One problem with double hung windows is that they are difficult to wash. In order to clean the outside of a double hung window, a person cleaning the window must go outside to clean the outside surface of the window or attempt to reach through the window, which is awkward.
In order to eliminate the problem of having to go outside or reach through to clean the outside surface of a window, some window sashes have been designed to tilt in from the window frame. Tilt-in windows typically have two manually operated retractors, one located on each side at the top surface of the upper rail of each window sash. To tilt the sash in, the retractor on each side of the window sash is retracted from its track, allowing the window sash to tilt in about a lower pivot axis of the window sash, typically at the lower rail. One problem with typical tilt-in windows is that it is difficult to simultaneously retract the retractors on both sides of the window sash. Two hands must be used at the same time, i.e., one hand for each retractor, to tilt the window in from the sliding position in the window frame.
In order to eliminate the problem of having to operate tilt-in windows using two hands, centrally located tilt-in handles or levers has been devised. See, for example, U.S. Pat. No. 5,992,907 entitled xe2x80x9cLock and Tilt Latch for Sliding Windowsxe2x80x9d issued to Sheldon et al. and U.S. Pat. No. 5,398,447 entitled xe2x80x9cCentrally Located Tilt-In Window Handlexe2x80x9d issued to Morse, the disclosures of which are herein incorporated by reference in their entirety.
While, these and other centrally located tilt-in handles or levers may be easier to operate than a pair of window sash retractors, some latch mechanisms are difficult to operate. Further, centrally located latches of this type, particularly those which provide both sash lock and tilt features, can have problems providing reliable and smooth operation over the life of the window. Also some centrally located tilt-in windows require a first lever to lock one window sash relative to the second window sash and a second lever to tilt the window in relative to a window frame, adding to the complexity and cost of the window hardware.
The present invention relates to a single lever tilt lock latch mechanism mounted to a first window sash that allows the window sash to be locked, opened, and tilted in.
The tilt lock latch mechanism includes a rotatable element mounted to a housing. The rotatable element includes a keeper that can be received in a receiver located in a second window sash to prevent relative sliding movement of the first window sash and the second window sash when engaged. The tilt lock latch mechanism further includes a retractable element disposable remote from the housing and a transmission connecting the rotatable element with the retractable element to permit the first window sash to be tilted away from the second window sash and window frame when the retractable element is retracted from its track in the window frame. In a first angular position, the rotatable element positions the rotatable element keeper in the receiver in a locked position to prevent relative sliding movement of the first window sash and the second window sash. In a second angular position, the rotatable element keeper is positioned in an open position to permit relative sliding movement of the first window sash and the second window sash. In a third angular position, the rotatable element is positioned in a tilt position, retracting the retractable element to permit the first window sash to be tilted away from the second window sash and the window frame. In operation, the rotatable element rotates serially from the first angular locked position to the second angular open position to the third angular tilt position.
In one embodiment, the tilt lock latch mechanism transmission includes a ligament connected to the retractable element, which is biased in an extended position in the window frame track. The tilt lock latch mechanism may include a single lever for manual actuation of the rotatable element.
In another embodiment, the invention includes a tilt lock latch mechanism for use in a window assembly. The window assembly includes a window frame having a pair of window frame slots or tracks, a first window sash, a second window sash, and a pair of retractable tilt latches on opposite ends of the top rail of the first window sash. The retractable tilt latches are in communication with respective window frame slots for supporting the first window sash in sliding relation with the window frame. The tilt lock latch mechanism has a housing mounted on the first window sash. The tilt lock latch mechanism also has a rotatable element, including a keeper, which is mounted on the housing. A receiver is mounted on the second window sash to accept the rotatable element keeper to prevent relative sliding movement between the first window sash and the second window sash when the rotatable element is moved to a locked position and to permit relative sliding movement between the first window sash and the second window sash when moved to an open position. The tilt lock latch mechanism further includes a transmission interdisposed between the rotatable element and the pair of retractable tilt latches, wherein the pair of retractable tilt latches are retracted from the window frame slots when the rotatable element is moved beyond the open position to a tilt position, permitting the first window sash to be tilted relative to the window frame. The rotatable element rotates serially from the locked position to the open position to the tilt position.